1. Field of the Invention
This invention relates to a printing device for use with a personal computer or as a terminal device of an office computer.
2. Description of the Prior Art
In recent years, printing devices which enable a selection of the type of interface for connection with a host computer and the method of processing information have been developed.
Many printing devices of the type described above have DIP switches which are arranged to be appropriately switched for the purpose of selecting the aforesaid various functions.
However, as the functions of a printing device increase, the number of DIP switches required for setting the functions also increases. Therefore, the user's task of setting the DIP switches becomes complicated.
In order to solve this problem, a recently-developed printing device has various selection switches and a display device, and the user can set the various functions by looking at information displayed on the display device and operating the various selection switches.
An example of a device of the type described above will now be described.
FIG. 5 shows the structure of an operation panel portion of a printing device of the type described above, and Table 1 shows the various modes which can be set for this printing device.
As shown in this table, the user can select a desired data item from data items which have been classified into a three-step hierarchy consisting of GROUP, FIELD, and ITEM so that he can set that function for the device.
TABLE 1 ______________________________________ GROUP FIELD ITEM ______________________________________ 1. EMULATION EMULATION DAISY PRINTER INTERFACE DOT PRINTER SELECTION INTERFACE RS232C SERIAL CENTRONICS 2. RS232C PROTCOL DTR+ INTERFACE DTR- SET-UP XON/XOFF ETX/ACK BAUD RATE 300 600 1200 2400 4800 9600 PARITY NO EVEN ODD DATA BITS 7 BITS 8 BITS STOP BITS 1 BIT 2 BITS 3. FONT SET-UP RESIDENT COURIER 10 COURIER 12 GOTHIC 15 OPTION FONT #1 FONT #2 FONT #3 4. CONTROL CODE CR ACTION CR ONLY SET-UP CR+LF LF ONLY LF+CR FF ONLY FF+CR ______________________________________
The case where an operator sets `RS232C INTERFACE SET-UP` as GROUP, `BAUD RATE` as FIELD, and `1200` as ITEM will now be described as an example.
In this case, the operator first presses a GROUP key 26, whereby the first data item `EMULATION INTERFACE SELECTION` of GROUP is displayed on a liquid-crystal display (abbreviated to `LCD` hereinafter) 25. Then the operator presses a SELECT key 29 once, whereby the information displayed by the LCD 25 is changed to `RS232C INTERFACE SET-UP`. He then presses an ENTER key 23 to select `RS232C INTERFACE SET-UP` as GROUP. Subsequently, the operator presses a FIELD key 27, whereby `PROTCOL` is displayed by the LCD 25, then presses the SELECT key 29 once to make the LCD 25 display `BAUD RATE`. The operator presses an ENTER key 30 to select `BAUD RATE` for FIELD, then presses an ITEM key 28, whereby `300` is displayed by the LCD 25. He then presses the SELECT key 29 twice, whereby the information displayed by the LCD 25 is changed to `1200`. When `1200` is displayed, `1200` can be selected as ITEM by pressing the ENTER key 30, and the sequence of operations for determining the function is completed.
However, when the above operations of determining the function is carried out, since the operator must press each of the GROUP key 26, FIELD key 27, ITEM key 28, SELECT key 29, and ENTER key 30, the operation is complicated.
Furthermore, when the operator selects the function, he must operate the keys after memorizing the hierarchy which is currently set. This leads to operator error.